When producing an electrical storage module using a square electrical storage device (energy storage cell), a plurality of electrical storage devices are stacked using a bus bar (conductive plate). The bus bar is placed so as to come in contact with a terminal plate provided to a sealing plate, and the plurality of electrical storage devices are connected in series through the bus bar to obtain an electrical storage module, for example (see JP-A-2010-80355, for example).
In recent years, the size of the electrical storage device has been increasingly reduced, and it has become indispensable to reduce the size of each member included in the electrical storage device. Since the area of the terminal plate decreases when the size of the casing is reduced, the area of contact between the terminal plate and the bus bar tends to decrease, and the contact resistance between the terminal plate and the bus bar may increase. The size of a holder that holds the sealing plate decreases when a situation in which the contact resistance between the terminal plate and the bus bar increases is prevented by the sacrifice of part of the holder. In such a case, when a torque pressure is applied in the rotation direction of a nut when securing the bus bar on the terminal plate by fitting a nut to a bolt, the holder may be tilted in the rotation direction, and the holding power of the holder that holds the terminal plate may decrease, whereby the terminal plate may be displaced from a predetermined position, for example. As a result, the terminal plate may be disconnected from an electrode assembly placed inside the casing.